Tau-square guide



March 30 1926. v 1,578,586

- T. M. DAVIS '1 SQUARE- GUIDE Filed April 4, 1925 u i @i.

. NETS Patented Mar. 30, 1926.

res ear-Ear series;

THOMAS m. DAVIS, or Los Antennas, CALIFORNIA, Assrenon or ONE-HALF .To 1

,"EDWARD w. McKINNEY, onLosanennnscnmronnm. I a

T-SQUARE Quinn;

Application filed April 4, .1925. Serial .No. 20,7165

Tod whom it may concern: lie-it known that I, THOMAS M. DAVIS, a citizen of the United States, residing at Los Angeles, inthe county of Los Angeles. State of California, have invented a new and useful T -Square Guide, of which the following is a specification.

This invention relates to a device for guiding a T-square as it is. moved to and fro along the drawing board, an object being to hold the cross head of the i this character that will operate properly refill gardless of the relative lengths of the drawing board and T-square. a

Further objects and advantages will appear in the subjoined detailed description.

The accompanying drawings illustrate the invention:

Fig. 1 is a plan view of a T-square guide constructed in. accordance with the provisions of this invention and applied to a drawing board.

l ig. 2 is an edge view looking up toward Fig. 1.

Fig. 3 is an enlarged broken elevation, partly in section, from the line lndicated by 3 3, Fig. 1. p

Fig. 4 is an enlarged fraginental sectional detail on the line indicated bye-, Fig. 1.

The T-square indicated at a. is provlded with a shoulder 6 adapted to engage and be guided by a member 7 which is mounted substantially parallel with one edge of the drawing board, indicated at b. In this particular instance, the shoulder 6 is constituted'by a roller mounted on a shaft 8 which is detachablv secured to the T-square. The shaft/8 is screw-threaded into one leg of a U-shaped clamp 9 and the other leg of said clamp is provided with a set screw 10 adapted to be threaded onto the arms 13.

"crewed into engagement with the underboard. "The construction for elfecting this is as follows: The flattened rodportions 11 are provided with longitudinally extending slots 12 through which pass arms 13 secured by screw 14 or other suitable fastening devices to opposite edges of the drawing board. The arms 13 are each provided with an an nular bend 15 so that the outer end portions of the arms that extend through the member 7 lie in a plane above the level of the upper face of the drawing board, thus holding the member 7 above the head of the T-square and in alignment with the roller 6.

The arms 13 are provided near their outer ends with shoulders 16 which, in this instance, are constituted by nut screws Interposed between the fiattened ends 11 and the ends 16 are coil springs lfi which surround the arms T he springs 17 yieldingly hold the member 7 in engagement with the roller 6 so as to yieldingly hold thehead c of the T-square in contact with the adjacent edge of the drawing board. I d

When the draftsman is using the invention described above, he will place his hand upon the blade of the T-square and force it away from ortoward him, and the roller 6 and the member 7 will guide the T-square as it moves to and fro over the drawing board. The invention operates a great deal the same asthough the draftsman employed his hand uponthe head of the T-square, as is customary, to press said head against the drawing board but by using this invention the pressure is uniform and the draftsman is relieved from exerting the required pressure. I v v If desired, for any reason, to use the T- square on the drawing board in such manner that the invention would interfere with its proper manipulation, the screw 10 will be loosened and the clamp 9 removed so that the member 7 will -no longer function to yieldingly press the head of the T-square toward the drawing board.

I claim: a i g 1. A T-square guide comprising arms adapted to be secured to and project from a drawing board, a rod having its opposite ends slidably engaging the arms respectively, a T-square having a shoulder, and springs on the arms yieldingly holding the rod engaged with the shoulder to urge the T-sq uare against an edge of said board.

A T-square guide comprising a rod, means to slidably connect the rod at its 0 posite ends to a drawing board substantially parallel with one edge thereof, springs operating to hold the rod toward the drawing board, and a T-square having a shoulder on the upper face of the cross-head thereof positioned to engage the inner side of the rod when the T-square is lying on the drawing board.

3. A T-square guide comprising arms adapted to be secured to and project from a drawing board, said arms having bends therein to .eause the outer end portions of the arms to lie in a plane above the level of the upper face of the drawing board, arod slidably connected with the outer end portions of the arms, a T-square having a shoulder on its'upper face, and means yieldingly holding the rod toward the shoulder when the T-square is lying on the drawing board.

a. A T-square guide comprising a roller, means to detachably mount the roller on a T-square, a rod, means to connect the rod to a drawing board and permit movement of the rod toward and from oneedge of the board, and means yieldingly holding the rod in engagement with the roller to urge the T-square against an edge of said board.

Signed at Los Angeles, California this 26th day of March 1925.

THOMAS, M. DAVIS. 

